Arrangement of a motor on a support winch

ABSTRACT

An arrangement of a motor ( 1 ) on twin landing gears ( 2   a   , 2   b ) is described. The landing gears ( 2   a   , 2   b ) are interconnected via a connecting shaft and can be telescoped by starting up the motor ( 1 ). To minimize damage to the motor and at the same time to ensure cost-effective production, it is provided that the motor ( 1 ) with its driveshaft ( 5 ) engages with the connecting shaft ( 4 ) and is supported on a component that is fixed relative to the motor ( 1 ).

[0001] The invention relates to an arrangement of a motor on twinlanding gears, particularly on a semi-trailer of a tractor-trailer, suchthat the landing gears are interconnected via a connecting shaft and canbe telescoped by starting up the motor.

[0002] After coupling or uncoupling the semi-trailer, the landing gearsare telescoped, i.e. they are extended or retracted, and support thestanding semi-trailer. This extending and retracting of the landinggears is usually done by the driver using a hand crank that is mountedon one of the landing gears. To relieve the driver of this physicallystrenuous work, efforts are being made to apply the power required toretract and extend the landing gears by a motor.

[0003] Such an arrangement of a motor on a landing gear is disclosed inEP 0 179 632. The motor is mounted to one of the landing gears from theoutside—in place of the hand crank—to a primary shaft of the landinggear gearbox. The essential drawback of the power-driven landing gear ofthe prior art is that the motor is mounted on the outside of the landinggear in an unprotected area and, in practice, is frequently damaged. Afurther drawback is that the motor must be designed for a low speed anda high speed of the landing gear, which entails substantial motor designcomplexity because it requires either a motor control or an additionalmotor speed.

[0004] Thus, the object of the invention is to provide an arrangement ofa motor that minimizes damage to the motor and at the same time can beproduced cost-effectively.

[0005] According to the invention, this object is attained by anarrangement in which the motor with its driveshaft engages with theconnecting shaft and is supported on a component that is fixed relativeto the motor.

[0006] By supporting the motor on a fixed component, co-rotation of themotor is effectively prevented and, as a result, a rotation of theconnecting shaft is realized.

[0007] By positioning the motor on the connecting shaft, the problem ofadjusting the motor to the typically two-speed gearbox of the landinggear is solved by arranging the motor behind the gearbox in the line offorce. As a result it is possible, in turn, to use commerciallyavailable, simply constructed motors.

[0008] A further advantage of the arrangement according to the inventionis that the motor is mounted in a protected area between the landinggears, in the case of semi-trailers underneath the semi-trailer floorand thus cannot be easily damaged during travel.

[0009] Furthermore, the landing gears do not need to be modified forretrofitting, or the manufacturer can use the same components fordifferent landing gear types.

[0010] In a special embodiment, a spring element is arranged between themotor and the fixed component.

[0011] The spring element prevents damage to the motor when the landinggear drives against its upper or lower limit stop as the motor is stillcoasting due to its centrifugal mass. The elasticity of the springelement protects the motor against an abrupt load, especially whendriving against the upper hard limit stop, but also when starting up themotor. This extends the life of the motor and also allows the use ofless expensive motors.

[0012] The spring element preferably is a spiral spring, particularly acoil spring, a torsion element or a shock absorber. The spiral springcan be installed in its axial extension or can be used as a torsionelement. The term shock absorber should be understood as includingspring buffers.

[0013] A torsion element may also be an elastic hose or an elastic tube.

[0014] The fixed component is advantageously at least one of the twolanding gears and in this case especially preferably the rear side ofthe landing gear mounting plate by means of which the landing gear isscrewed to the semi-trailer.

[0015] The spiral spring or the torsion element is advantageouslynon-rotatably mounted to at least one of the landing gears and to themotor, such that when the landing gear is driven against a limit stop,the entire motor is gently supported in its direction of rotation.

[0016] The spiral spring or the torsion element preferably surrounds theconnecting shaft at least partially.

[0017] It has proven to be particularly advantageous if the connectingshaft is arranged contactless within the spiral spring or the torsionelement. This prevents friction losses between the connecting shaft andthe spiral spring or the torsion element as the landing gear istelescoped.

[0018] In an alternative embodiment, the fixed component is theunderside of the semi-trailer floor. In this case, the spiral spring orthe shock absorber can be arranged between the motor and the undersideof the semi-trailer floor.

[0019] It has proven to be advantageous if the spiral spring has anupper and a lower partial spring arranged on a guide tube, and the outerends of these partial springs can be fixed by an end stop. Between theupper and the lower partial spring, a mounting bushing is arranged onthe guide tube. Preferably, the mounting bushing or the shock absorberis connected with the motor at a stop point. This stop point may allowthe motor to pivot relative to the mounting bushing. When the landinggear is extended, the motor, due to its startup torque, could, forexample, compress the upper partial spring via the mounting bushing, sothat an abrupt loading of the motor and the components in the line offorce downstream thereof is avoided. When the landing gear is extendedcompletely, the foot of the landing gear touches the ground, i.e. thelanding gear has reached its lower limit stop. The motor, however,continues to rotate for a brief time because of its centrifugal mass, sothat the mounting bushing again presses against the upper partial springand an abrupt loading is consequently avoided. Since the motor changesits direction of rotation when the landing gear is retracted, the lowerpartial spring is compressed both during startup and when drivingagainst the upper limit stop.

[0020] Advantageously, the guide tube is placed onto an inner tube andcan be connected with the inner tube in different positions in axialdirection. This makes it possible to adjust and adapt the guide tube tothe spatial conditions of the specific application to ensure optimizedcooperation of the mounting bushing clamped by the partial springs andthe motor fixed at the stop point.

[0021] In the above-described embodiments, the connecting shaft can benon-rotatably mounted on the driveshaft. This makes it possible torealize a loss-free and maintenance-free power transmission.

[0022] In a further advantageous embodiment, a spring element isarranged between the driveshaft and the connecting shaft. In contrast tothe above-described embodiments, an elastic element is introduceddirectly in the line of force between the driveshaft of the motor andthe connecting shaft.

[0023] The spring element can be an elastic sleeve, a belt drive or aslip coupling. The elastic sleeve is made of an elastic material, e.g.rubber.

[0024] The elastic sleeve is advantageously configured as an air chambersleeve. This air chamber sleeve comprises an inner circumferential walladapted to the outer wall of the connecting shaft and an outercircumferential wall adapted to the inner wall of the driveshaft. Theinner and outer circumferential walls are connected via radiallyextending partitions that are spaced apart from one another. Airchambers are formed between the partitions. If shock-like forces occur,a damping effect is achieved due to the material properties and thematerial displacement by applying a force in circumferential direction.

[0025] In a particularly preferred embodiment, the fixed componentconsists of at least one of the landing gears, a semi-trailer floor or astructural member of the vehicle, such that the fixed component isrigidly connected with the motor.

[0026] This has the advantage, first of all, that a smaller clearance isrequired because there are no spring elements that elastically supportthe motor. In particular, the space available between the connectingshaft and the underside of the semi-trailer floor is often tight. Due tothe rigid mounting of the motor, incoming lines to the motor do not haveto be flexible. A further safety aspect is that there are no movingparts on the outside. In addition, the weight forces of the motor aresupported via the fixed mounting and are not transmitted via theconnecting shaft to the bearings of the landing gear, which wouldotherwise be subject to greater wear.

[0027] Advantageously, the elastic sleeve is non-rotatably mounted onthe connecting shaft and the driveshaft. This can be accomplished, forexample, by bonding or vulcanizing.

[0028] In one advantageous embodiment, the belt drive has a drive beltwhich loops around a driving wheel that is non-rotatably mounted on thedriveshaft and a driven wheel that is non-rotatably mounted on theconnecting shaft.

[0029] The drive belt can be made of an elastic material.

[0030] As an alternative to an elastic drive belt, a fixed, flexiblymounted tension roller can engage with a drive belt that has littleelasticity. In the quasi-stationary operating state, i.e. as the landinggear is telescoped, a pretensioning force is applied to the drive beltvia the flexibly mounted tension roller. When the landing gear reaches alimit stop, the tension roller is pushed back by the drive belt and thusdampens the shock-like load.

[0031] In a further advantageous embodiment, the slip coupling has adriving gear wheel with internal teeth, which is mounted on thedriveshaft and engages with a complementary driven gear wheel withexternal teeth, which is mounted on the connecting shaft. The drivinggear wheel and/or the driven gear wheel are mounted on the driveshaft orthe driven shaft in a non-positive fit with a predefined frictioncoefficient. In case of an abrupt load, at least one of the gear wheelsslips on its shaft in circumferential direction and thereby prevents theshock from being transmitted to the motor.

[0032] It has proven to be particularly advantageous if the driveshaftis configured as a hollow shaft. This has the advantage that thecommonly used connecting shaft can be pushed through the driveshaftconfigured as a hollow shaft and as a result can continue to be used toa limited extent.

[0033] The hollow shaft can have a circular cross section. This, inturn, simplifies the power transmission from the motor to thedriveshaft.

[0034] The motor is preferably not self-locking, i.e. in case of a powerfailure or some other malfunctioning of the motor, the landing gear canstill be moved by means of a hand crank as before.

[0035] The motor preferably is an electric motor. An electric motor iscost-effective, low-maintenance, compact and easy to connect by means ofa power cable, independent of a compressed air supply.

[0036] The motor is advantageously designed for a torque of 5 to 15 Nm.

[0037] The invention will now be described in greater detail, by way ofexample, with reference to the drawing figures, in which:

[0038]FIG. 1 is a schematic back view of an arrangement of a motor onthe connecting shaft with fixed support relative to a landing gear,

[0039]FIG. 2 is a partial view of an elastic support of the motor on alanding gear,

[0040]FIG. 3 is a perspective view of an elastic support of the motor onthe semi-trailer,

[0041]FIG. 4 is a back view of a support according to FIG. 3,

[0042]FIG. 5 is a longitudinal section of the motor with driveshaft,elastic sleeve and connecting shaft,

[0043]FIG. 6 is a cross section of an air chamber sleeve, and

[0044]FIG. 7 is a schematic side view of a belt drive.

[0045]FIG. 1 shows twin landing gears 2 a, 2 b arranged on asemi-trailer 3, which touch the ground when extended. A hand crank 29may be seen on the landing gear 2 a, which can be used to move thelanding gears 2 a, 2 b if the motor 1 fails. The landing gears 2 a, 2 bare screwed to the semi-trailer 3 via a landing gear mounting plate 31.Each of the landing gears 2 a, 2 b, is equipped with a landing geargearbox.

[0046] The motor 1 is disposed on the connecting shaft 4 thatinterconnects the two landing gears 2 a, 2 b and with its driveshaft 5non-rotatably encloses the connecting shaft 4. Via a spring element 6,which in the present case is configured as a torsion element 8, themotor 1 is elastically connected with the landing gear 2 b and at thesame time is secured against co-rotation. The torsion element can alsobe configured as an elastic hose 10 or an elastic tube.

[0047] In FIG. 2, the motor 1 is elastically connected with the landinggear 2 b by means of a spiral spring 7 instead of a torsion element 8.The connecting shaft 4 runs through the center of the spiral spring 7.

[0048]FIG. 3 is a perspective view of an alternative embodiment in whichthe motor 1 is supported on the underside of a semi-trailer floor 11(see FIG. 1) by means of a spring element 6.

[0049] In a center area of the motor, the rotatable driveshaft 5protrudes on both sides.

[0050] The motor 1 is supported via the stop point 17 and the mountingbushing 16, which in turn is clamped between the upper partial spring 14and the lower partial spring 15. The partial springs 14, 15 are eachplaced onto a guide tube 9 and are fixed at their outer ends 13 a, 13 bby means of end stops 12 a, 12 b.

[0051] To enable the spring element 6 to be mounted on structurallydifferent semi-trailers, the guide tube 9 can be mounted so as to bedisplaceable in axial direction 19. For this purpose, the adjustingbolts 35 are pulled out, the guide tube 9 and the partial springs 14, 15as well as the mounting bushing 16 are shifted relative to the innertube 18, which can be mounted to the underside of the semi-trailer (notdepicted) by means of the mounting plate 32, and the adjusting bolts 35are reinserted in the desired position, e.g. in one of the differentvisible positions 20 a, 20 b, 20 c. Thus, the position of the motor 1can be adapted to a predefined position of the connecting shaft 4without any change in the elastic properties of the spring element 6.

[0052]FIG. 4 shows the spring element 6 and the motor 1 in a back view,so that the motor 1 covers the upper and lower partial springs 14, 15.The spring element 6 is connected with the bolting plate 32 by means ofa screwed connection 33.

[0053]FIG. 5 is a section of a motor 1, wherein a spring element 6 inthe form of an elastic sleeve 21 is arranged between the driveshaft 5and the connecting shaft 4. The elastic sleeve 21 is brought out of themotor 1 on one side and has a bore 36 that extends through the elasticsleeve 21 and the connecting shaft 4, through which a connecting bolt 34is pushed. By means of the connecting bolt 34, the elastic sleeve 21 andthe connecting shaft 4 are interconnected in a positive lockingconnection and are thus secured against rotation. The driveshaft 5 isalso connected with the elastic sleeve 21, e.g. by bonding.

[0054] In the embodiment according to FIG. 5, the motor 1 can be rigidlymounted to the underside of the semi-trailer floor 11, since theelasticity required when the landing gear 2 a, 2 b is driven against alimit stop is provided between the driveshaft 5 and the connecting shaft4.

[0055]FIG. 6 shows an air chamber sleeve 24 as a special form of theelastic sleeve 21. By way of example, the air chambers 24 a are shown ina relaxed state, while the air chambers 24 b are depicted under load.The air chamber sleeve 24 is non-rotatably mounted between thedriveshaft 5 and the connecting shaft 4.

[0056] An alternative spring element 6 is shown in FIG. 7 in the form ofa belt drive 22. Here, a driving wheel 26 drives a driven wheel 27 via adrive belt 25. The driving wheel 26 is non-rotatably connected with thedriveshaft 5 while the driven wheel 27 is non-rotatably connected withthe connecting shaft 4.

[0057] Tension rollers 28 engage with the drive belt 24 from the outsideon both sides to pretension the belt. As the landing gear 2 a, 2 b istelescoped against a limit stop, the drive belt 25 presses against oneof the tension rollers 28 such that the impact is absorbed. List ofReference Numerals  1 motor  2a, b landing gear  3 semi-trailer  4connecting shaft  5 driveshaft  6 spring element  7 spiral spring  8torsion element  9 guide tube 10 elastic hose 11 underside ofsemi-trailer floor 12a, b limit stop 13a, b outer end of partial spring14 upper partial spring 15 lower partial spring 16 mounting bushing 17stop point 18 inner tube 19 axial direction of guide tube 20a, b, cdifferent positions 21 elastic sleeve 22 belt drive 24 air chambersleeve 24a air chamber without torsional load 24b air chamber withtorsional load 25 drive belt 26 driving wheel 27 driven wheel 28 tensionroller 29 hand crank 30 landing gear gearbox 31 landing gear mountingplate 32 bolting plate 33 screwed connection to bolting plate 34connecting bolts 35 adjusting bolts 36 bore

1. Arrangement of a motor (1) on twin landing gears (2 a, 2 b),particularly on a semi-trailer (3) of a tractor-trailer, wherein thelanding gears (2 a, 2 b) are interconnected via a connecting shaft (4)and can be telescoped by starting up the motor (1), characterized inthat the motor (1) with its driveshaft (5) engages with the connectingshaft (4) and is supported on a component that is fixed relative to themotor (1).
 2. Arrangement as claimed in claim 1, characterized in that aspring element (6) is arranged between the motor (1) and the fixedcomponent.
 3. Arrangement as claimed in claim 2, characterized in thatthe spring element (6) comprises a spiral spring (7), a torsion element(8) or a shock absorber.
 4. Arrangement as claimed in claim 3,characterized in that the torsion element (8) comprises an elastic hose(10).
 5. Arrangement as claimed in any one of claims 2 to 4,characterized in that the fixed component is at least one of the twolanding gears (2 a, 2 b).
 6. Arrangement as claimed in claim 5,characterized in that the spiral spring (7) or the torsion element (8)is non-rotatably mounted to at least one of the landing gears (2 a, 2 b)and to the motor (1).
 7. Arrangement as claimed in claim 5 or 6,characterized in that the spiral spring (7) or the torsion element (8)at least partially surrounds the connecting shaft (4).
 8. Arrangement asclaimed in any one of claims 4 to 7, characterized in that theconnecting shaft (4) is arranged contactless within the spiral spring(7) or the torsion element (8).
 9. Arrangement as claimed in claim 2 or3, characterized in that the fixed component is the underside of asemi-trailer floor (11).
 10. Arrangement as claimed in claim 9,characterized in that the spiral spring (7) or the shock absorber isarranged between the motor (1) and the underside of the semi-trailerfloor (11).
 11. Arrangement as claimed in claim 10, characterized inthat the spiral spring (7) comprises an upper (14) and a lower (15)partial spring disposed on a guide tube (9), and the outer ends (13 a,13 b) of said partial springs (14, 15) can each be mounted via a limitstop (12 a, 12 b), wherein a mounting bushing (16) is disposed on theguide tube (9) between the upper and the lower partial spring (14, 15).12. Arrangement as claimed in claim 11, characterized in that themounting bushing (16) or the gas shock absorber is connected with themotor (1) at a stop point (17).
 13. Arrangement as claimed in claim 11or 12, characterized in that the guide tube (9) is placed onto an innertube (18) with which it can be connected in various positions (20 a, 20b, 20 c) in axial direction (19).
 14. Arrangement as claimed in any oneof claims 1 to 13, characterized in that the connecting shaft (4) isnon-rotatably mounted on the driveshaft (5).
 15. Arrangement as claimedin claim 1, characterized in that a spring element (6) is arrangedbetween the driveshaft (5) and the connecting shaft (4).
 16. Arrangementas claimed in claim 15, characterized in that the spring element (6) isan elastic sleeve (21), a belt drive (22) or a slip coupling. 17.Arrangement as claimed in claim 16, characterized in that the elasticsleeve (21) is configured as an air chamber sleeve (24).
 18. Arrangementas claimed in any one of claims 15 to 17, characterized in that thefixed component is at least one of the landing gears (2 a, 2 b), asemi-trailer floor or a vehicle support member, wherein the fixedcomponent is rigidly connected with the motor (1).
 19. Arrangement asclaimed in any one of claims 16 to 18, characterized in that the elasticsleeve (21) is non-rotatably mounted on the connecting shaft (4) and thedriveshaft (5).
 20. Arrangement as claimed in any one of claims 16 to18, characterized in that the belt drive (22) comprises a drive belt(25), which loops around a driving wheel (26) non-rotatably mounted onthe driveshaft (5) and a driven wheel (27) non-rotatably mounted on theconnecting shaft (4).
 21. Arrangement as claimed in claim 20,characterized in that the drive belt (25) is made of an elasticmaterial.
 22. Arrangement as claimed in claim 20 or 21, characterized inthat a fixed, elastically supported tension roller (28) engages with thedrive belt (25).
 23. Arrangement as claimed in any one of claims 16 to18, characterized in that the slip coupling has a driving gear wheelwith internal teeth which is mounted on the driveshaft and engages witha complementary driven gear wheel with external teeth which is mountedon the connecting shaft, wherein the driving gear wheel and/or thedriven gear wheel is mounted on the driveshaft or the driven shaft in anon-positive fit with a predefinable friction coefficient. 24.Arrangement as claimed in any one of claims 1 to 23, characterized inthat the driveshaft (5) is configured as a hollow shaft.
 25. Arrangementas claimed in claim 24, characterized in that the hollow shaft has acircular cross section.
 26. Arrangement as claimed in any one of claims1 to 25, characterized in that the motor (1) is not self-locking. 27.Arrangement as claimed in any one of claims 1 to 26, characterized inthat the motor (1) comprises an electric motor.
 28. Arrangement asclaimed in any one of claims 1 to 27, characterized in that the motor(1) is designed for a torque of 5 to 15 Nm.